A method employed for industrially producing a conjugated diolefin, for example, 1,3-butadiene (hereinafter also referred to as “butadiene”) is to extract BBP (mainly a hydrocarbon mixture having 3 to 5 carbon atoms) obtained from naphtha cracking into a solvent and selectively remove butane, butene, acetylenes, high boiling components, low boiling components, etc.
In contrast, Patent Documents 1 and 2 disclose methods for producing butadiene from butene. In these methods, butene is subjected to oxidative dehydrogenation and quenched and the moisture is removed therefrom, followed by absorbing butadiene using a solvent for collection. Examples of easy methods for removing moisture which are commonly used include distillation and adsorption. Patent Documents 3 and 4 describe a method in which right butene is subjected to gas phase catalytic oxidative dehydrogenation in a fixed bed, the produced gas is cooled, high boiling by-products are removed and the aldehyde contained in the cooled gas is removed.